Bar-coding has become a near-ubiquitous way of encoding and storing information and, consequently, bar-code scanners used to read and decode bar-coded information have become extremely common. Among the most common type of scanners are the hand-held variety: typically shaped like a gun, the scanner is held by a user, pointed at the bar code, and activated by means of a trigger to cause the scanner to scan a laser beam across the bar code being read. To obtain a proper scan of a bar code, a hand-held scanner must be pointed at a bar code so that the bar code is within the fields of view of the scanning laser and of the photodetectors in the scanner that pick up optical energy from the scanning laser's reflection off the bar code. To assist a user in pointing the hand-held bar code scanner the scanning beam is designed to be visible, so that when the scanner is pointed at a surface the user can see the beam's trajectory on the surface. Since the beam's trajectory is visible, the user then can move the scanner until the trajectory of the beam crosses the bar code, as which point the bar code is within the scanner's field of view and can be read.
Using the trajectory of the scanning laser to properly point the scanner works well, provided the user can see the trajectory. For scanners used in locations where the ambient light is dim in comparison to the beam (e.g., most indoor applications) and where the distance from scanner to bar code is small, the trajectory is usually clearly visible. When used where the ambient light is very bright (e.g., most outdoor applications in direct sunlight) and/or where the distance between scanner and bar code is large, the beam's trajectory may not be visible to the user, and therefore cannot assist the user in pointing the scanner such that the laser's trajectory crosses the bar code.